Also along these lines, I like to use lines that start with if 0 and if 1 as additional debugging tools. I particularly use this approach with a little subroutine that invokes Dumper (I could probably do this directly, but anyway). Again, when I want the program to dump the object, it's easy to flip the '0' to '1', and when I'm done with the need to see such output, I can easily find all patterns of ^if 1 and flip the '1' back to '0'.